This application claims priority of French Patent Application No. 02 01147, filed on Jan. 31, 2002, entitled xe2x80x9cEjectable Door For Aircraftxe2x80x9d by Frederic Leclerc and which was not published in English.xe2x80x9d
The invention relates to an ejectable door designed to facilitate the emergency evacuation of an aircraft if necessary.
More precisely, the invention relates to an articulated xe2x80x9cplugxe2x80x9d type aircraft door that stops in contact with the mechanical elements fixed to the door frame, when it is in the closed position. In flight, the pressure on the inside of the cabin keeps the door closed, holding it in contact on some of these mechanical elements. The other mechanical elements support the weight of the door.
The invention is particularly applicable to military cargo type aircraft, designed for troop transport or equipment transport.
Commercial aircraft such as aircraft intended for passenger transport are usually fitted with xe2x80x9cplugxe2x80x9d type doors. In the case of an aircraft emergency evacuation, the doors are used by passengers as emergency exits when the aircraft is on the ground.
Document GB-A-2 181 780 describes a xe2x80x9cplugxe2x80x9d type aircraft door in which stops located on the door come into contact with mechanical elements fixed on the door frame, when the door is closed. The door is hinged on the frame by a hinge mounted on its bottom edge so that it opens tilting downwards, and vice versa. Means are provided to engage the stops on the mechanical elements of the frame during closure, and vice versa. When the door is opened, these means displace the door upwards before tilting it downwards.
Unlike a commercial aircraft, it must be possible to evacuate a military cargo type aircraft intended for troop or equipment transport in flight, if necessary depending on circumstances. Therefore in this case, the doors used for embarking have to be removed quickly to allow free passage for evacuation of the crew. It can be understood that a door like that described in document GB-A-2 181 780 cannot solve this problem.
Pyrotechnic means are known that are capable of ejecting the door to enable evacuation of the crew during flight if necessary. Nevertheless, these means create different problems such as maintenance, and risks associated with the presence of explosives and reliability. There is always a risk of failure or accidental triggering of these pyrotechnic means. Another problem is due to the irreversible nature of their triggering.
The purpose of the invention is to correct at least some of the disadvantages of xe2x80x9cplugxe2x80x9d type doors used on aircraft, and particularly military aircraft.
More precisely, the purpose of the invention is to enable fast evacuation in flight or on the ground of an aircraft equipped with xe2x80x9cplugxe2x80x9d type doors, without any risk and significantly reducing maintenance and reliability problems.
According to the invention, this result is obtained using an aircraft door comprising a frame that can be fixed to the fuselage of the aircraft, a panel articulated onto the frame by articulation means, stops and mechanical elements installed on the panel and on the frame respectively, so as to remain in mutual contact under the effect of the weight of the panel when the door is closed, and guide means inserted between the panel and the frame in order to automatically release/engage the stops with respect to the mechanical elements, at the beginning of opening and at the end of closing of the door respectively, characterized in that it also comprises means of ejection triggering, that can control mechanical disconnection of articulation means and a relative disengagement of the stops from the mechanical elements, the guide means enabling downwards displacement of the panel by gravity when the ejection triggering means are used.
Due to this arrangement, the door panel is automatically released and drops by gravity as soon as the ejection triggering means are actuated. Emergency evacuation of the aircraft is thus made possible without the use of pyrotechnic means with all the disadvantages mentioned above.
According to a preferred embodiment of the invention, the ejection triggering means are mechanical means. Note that as a variant, these ejection triggering means may also be electrical, pneumatic or hydraulic means without going outside the framework of the invention.
Advantageously, the articulation means comprise main hinges provided with pivot hinge pins that can be retracted by use of the said ejection triggering means to control disconnection of the articulation means.
In this case, the ejection triggering means preferably comprise a part mounted on the frame capable of rotating about a given rotation axis and rods connecting the said part to the pivot hinge pins.
Also advantageously, the ejection triggering means are capable of retracting the mechanical elements mentioned above inside the frame to release them from the stops, when the ejection triggering means are used.
Also advantageously, the guide means comprise rollers installed on the panel and guide ramps fixed to the frame, the said ramps being open towards the bottom to enable the panel to move downwards, by gravity, when the ejection triggering means are used.
According to one variant embodiment of the invention, the ejection triggering means also control at least one active mechanical ejector capable of pushing the panel downwards when the ejection triggering means are used.
In this case, the active mechanical ejector is preferably installed on an upper edge of the frame.
According to another variant embodiment of the invention, the articulation means are inserted between the lower edges of the panel and the frame, and at least one passive spring-loaded mechanical ejector is included in the articulation means, capable of pushing the panel downwards during disconnection of the articulation means.